1. Technical Field
The present invention relates to a method for manufacturing a semiconductor apparatus and the semiconductor apparatus. In particular, the invention relates to a method for manufacturing a semiconductor apparatus and the semiconductor apparatus by which the generation of defective crystallization during the manufacture can be suppressed without requiring a special production apparatus.
2. Related Art
A field effect type transistor formed on an silicon on insulator (SOI) substrate (hereinafter referred to as “SOI transistor”) has attracted attention for the usefulness because elements can be separated easily, it is latchup free, and it has a small source/drain junction capacity for example. A complete depletion type SOI transistor in particular, which consumes a low power and can be operated with a high speed and can be easily driven with a low voltage, has been actively researched in order to operate the SOI transistor with a complete depletion mode. SOI substrates used here include, for example, an Separation by Implanted Oxygen(SIMOX) substrate and a laminated substrate as disclosed in JP-A-2002-299591 and JP-A-2000-124092.
On the other hand, oxide silicon (SiO2) has a lower thermal conductivity than that of silicon (Si). Thus, an SOI device has an operating temperature that is higher than that of a conventional silicon device. This phenomenon is called as a self-heat effect that is one of causing factors of deteriorating the performance and reliability of the device.
The SOI transistor has another problem of a substrate floating effect. This effect causes influences according to one of which an end of a drain of an Nch transistor for example has a hole due to the impact ion and this hole is accumulated in the body, which deteriorates the pressure resistance.
In order to solve the problem as described above, a DSOI (Drain/Source on Insulator) transistor has been suggested in which only the source/drain has an SOI structure (see Ping He, et al. IEEE International SOI Conference, 2002, p55 for example).
The DSOI transistor disclosed in the publication by ping He, et al. has been manufactured by a method using the above SIMOX method. Specifically, a mask is firstly formed on the entirety of an silicon (Si) substrate and a window is formed at a part at which an SOI structure is desired to be formed (the part is source/drain in this case). Next, oxygen ion is ion-implanted with a high concentration while recognizing a part to be a box as a target. Thereafter, the Si substrate is annealed with a high temperature to form a SiO2 region at a depth of the box under the source/drain. According to this method, the SiO2 region is formed only under the source/drain and no SiO2 region is formed under a channel. Thus, this method could have suppress the self- heat effect and the substrate floating effect.
Jp-A-2002-299591 is an example of related art.
Jp-A-2000-124092 is an example of related art.
The publication by ping He, et al. (IEEE International SOI Conference, 2002, p55) is an example of related art.
However, the above method for manufacturing a DSOI transistor requires a Si substrate to be heated during the implantation of oxygen ion because the crystalline characteristic of the Si substrate must be maintained. Thus, a so-called “HOT-impra apparatus” is required. The above method also requires, in order to form a SiO2 region under the source/drain, “high temperature anneal furnace” capable of providing heat treatment with a temperature of 1300 degrees or more. In other words, the above method has required special apparatuses for performing the SIMOX method and electric power for operating them, which causes an increased cost and a larger burden to environment (problem 1).
Furthermore, the above method for manufacturing a DSOI transistor has caused a risk in which the oxygen ion implantation with a high concentration may cause defective crystallization in a Si substrate and this defect may cause an adverse effect on the device characteristic (problem 2).